Why do my eyes feel dry in the middle of the night?

Eyes that feel dry in the middle of the night are usually reacting to bedroom air. Heat running through winter nights, a fan or ceiling fan aimed at the bed, and a vent near the pillow all speed evaporation while you aren’t blinking. Redirect the airflow, add moisture to the room, and use a lubricating drop only as its label directs. Dryness that keeps waking you is worth an eye exam.

Dry eyes in the middle of the night: what’s going on

While you sleep, your eyelids are closed and you’re not blinking, so the tear film isn’t being refreshed the way it is during the day. For most people that’s fine. But if air is moving across the face, or the room’s humidity has dropped, the surface of the eye can dry enough to wake you, or to make you notice it the moment you surface from sleep to roll over.

The usual pattern is a scratchy, sandy feeling, a desire to rub, or the sense that your eyelids are sticking. Most of the time it settles after you blink a few times. If it happens every night, the bedroom is the first place to look.

Dry eyes when sleeping: check the bedroom air

Walk into your bedroom at night and notice what’s moving. Common culprits:

• A forced-air heating register near the bed, especially one that blows toward the headboard.
• A ceiling fan on high, or a box fan pointed at you. Our guide to dry eyes when sleeping with a fan on covers fan placement.
• A space heater running through the night beside the bed.
• A window air conditioner in summer, which pulls water out of the air as it cools.
• A CPAP mask that leaks air toward the eyes. If you use one, the guide to dry eyes from a CPAP mask explains who to talk to.

Winter is often the worst season because the heat cycles on through the coldest hours, just when you’re deepest asleep. A thermostat that drops a few degrees at night means the furnace runs less, and the air stays a little moister.

Small changes that help

• Turn or deflect any vent that points toward the bed, or close the register in the bedroom if the room stays warm enough.
• Run a humidifier in the bedroom and clean it regularly. A simple hygrometer shows whether it’s making a difference; does a humidifier help dry eyes? explains the numbers.
• Set a fan to oscillate away from your face, or move it to the foot of the bed.
• Put the phone down a while before sleep. Screens reduce blinking, and going to bed with eyes already dry makes nighttime discomfort more likely.
• Try a sleep mask that doesn’t press on the eyelids, which shields the eyes from moving air.

Dry eyes at night while sleeping vs. on waking

Waking up in the middle of the night with dry eyes and waking up in the morning with them are related but not identical. Middle-of-the-night dryness often lines up with when the heat or air conditioning cycles on, so it can help to note the time and check the thermostat schedule. Morning dryness tends to reflect the whole night’s air. Our guide to waking up with dry eyes in winter focuses on the morning side.

Some people find that their eyelids don’t seem to close fully when they sleep, which a partner might notice. That’s not something to sort out at home. Mention it to an eye doctor.

Using eye drops in the night

Quell’s directions read: Apply 1 drop 3 times per day in each eye. The label doesn’t give separate instructions for nighttime or for doses spread around sleep, so a drop at bedtime or during the night counts as one of those three. If you find yourself needing more, that’s a reason to talk to an eye doctor; our guide on using more than three drops a day explains why the label sets a number. For bedtime use in general, see can you use eye drops before bed?.

A few practical notes for using a drop half asleep:

• Turn on a light. Aiming in the dark is how a tip ends up touching an eyelash or your fingers, and the label is clear: Do not touch tip of bottle to any surface to avoid contamination.
• Keep the bottle on the nightstand in a small dish or case, cap on, so it doesn’t roll under the bed.
• Check that it’s the right bottle. A medicine bottle beside the bed should never be confused with something else.
• Mind the storage range: Store between 15° to 30°C (59° to 86°F). A nightstand next to a radiator or a space heater can run warmer than that.

If your vision is a little blurry right after a drop, blink a few times and wait before getting up and walking around. The label’s Uses line reads: For use as a protectant against further irritation or to relieve dryness of the eye.

Dry eyes at night only

When your eyes feel fine during the day and dry only at night, the environment explanation becomes even more likely, because the bedroom is the one thing that changes. Experiment with one change at a time for a few nights, such as the fan off, then the humidifier on, so you can tell what made the difference.

If nothing in the room helps, or the dryness comes with pain, light sensitivity or vision that stays blurry, stop guessing. The label says: Stop use and ask a doctor if you feel eye pain or changes in your vision, if irritation or redness continues, or if the condition worsens or persists for 72 hours. Working out the cause belongs to an eye doctor. Our list of eye symptoms that need a doctor covers the signs not to wait on.